Re: Patch text in git-add patch mode lacks whitespace highlighting

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Feb 3, 2020, 12:37 UTC
Message-ID: <nycvar.QRO.7.76.6.2002031320180.46@tvgsbejvaqbjf.bet>
In-Reply-To: <20200203085456.GD2164@coredump.intra.peff.net>

Hi Peff,

On Mon, 3 Feb 2020, Jeff King wrote:

Show 20 quoted lines

> On Sat, Feb 01, 2020 at 10:06:43PM +0100, Johannes Schindelin wrote:
>
> > > > If my reading is correct, and we want `git diff-files --color` to respect
> > > > the `diff.wsErrorHighlight` setting, then this patch fixes that:
> > > > [...]
> > > > The bigger question is whether other core developers agree with this? And
> > > > what other `diff.*` settings should be respected by `git diff-files` (and
> > > > of course, `git diff-index`)?
> > >
> > > I think you can take my posting of an identical patch elsewhere in the
> > > thread as a "yes". :)
> >
> > Thank you ;-)
> >
> > That answer only applies to the first question, though. The second
> > question, whether other `diff.*` settings would like to enjoy the same
> > treatment, is still open for debate...
>
> I hoped you would read the other part of the thread where I mused on
> that same question. :)

Sorry, I totally missed that. Will re-read.

> The short of my answer is that I think the color-moved stuff might be a
> candidate, but it's sufficiently different that I think it should be
> decided on as a separate patch.

I actually wonder whether we should do something completely different. The problem with `git diff-files --color`, after all, is that `diff-files` was never intended to produce user-facing output, so the `--color` is somewhat of a contradiction here. The fact that `diff-files` is a low-level (or "plumbing") command means that by nature, it wants to control a lot more what the user-provided config can change (typically, scripts calling `diff-files` expect a certain format, and it would not do at all to heed `diff.noPrefix`, for example.

In that respect, `git add -p` using `diff-files` is kind of wrong: we _want_ to show the result to the user, with no processing at all (execpt the user-provided `diffFilter`).

So why not introduce a new option to `diff-files` and `diff-index` to ask it _specifically_ to heed diff UI config settings? I.e. a command-line option that makes it call

        git_config(git_diff_ui_config, NULL);

instead of

        git_config(git_diff_basic_config, NULL); /* no "diff" UI options */

Ciao, Dscho